Bi-fold doors for large openings are not new and are seen frequently in buildings such as aircraft hangers, automotive shops, farm barns and the like. Prior art construction of such bi-fold overhead doors are shown in:
______________________________________ Egleston 3,024,838 03/13/1962 Alton 3,504,729 04/07/1970 Pollock 4,088,172 05/09/1978 DeVore 4,243,091 01/06/1981 Geisthardt 4,509,291 04/09/1985 List 4,545,418 10/08/1985 Keller 4,609,027 09/02/1986 Johnson 4,903,747 02/27/1990 Keller 5,168,914 12/08/1992 ______________________________________